add benchmark for sparse cases

[stdpain]

add benchmark #319

batch_size=100, max=100 costs:79.486
batch_size=100, max=1000 costs:73.659
batch_size=100, max=1000000 costs:89.071
batch_size=100, max=100000000 costs:157.993
batch_size=100, max=10000000000 costs:140.42
batch_size=100000, max=1000 costs:80.9777
batch_size=100000, max=100000 costs:40.0966
batch_size=100000, max=1000000000 costs:260.795
batch_size=100000, max=100000000000 costs:457.955
batch_size=100000000, max=100000000 costs:97.4973
batch_size=100000000, max=500000000 costs:222.872
batch_size=100000000, max=5000000000 costs:464.429

[lemire]

Merged